1. Field of Invention
The present invention relates to roofing tiles of a type typically used on residential and other non-industrial buildings. More particularly, the invention relates to lightweight roofing tiles that are molded from a plastic-composite material to simulate conventional tiles and certain types of shingles.
2. Description of Prior Art
Roofing tiles and shingles are available in a variety of styles and materials. Conventional roofing tiles are typically concrete, clay or ceramic tiles provided in many styles, such as Roman or Spanish-S style. Specialty-type shingles include slate and cedar shake shingles. Such tiles and shingles generally offer longer life and less maintenance potential as compared with asphalt shingles, and they provide opportunities for unique and exotic roofing aesthetics not available with asphalt shingles. However, conventional roofing tiles and specialty-type shingles suffer from several drawbacks and disadvantages. In general conventional roofing tiles are relatively heavy, and they are not easily stacked for transportation to the job site or for carrying from the ground to the roof. The tiles must often be hand stacked and securely bound for transportation, and the heavier tiles must be carried to the roof a few at a time, or with the use of large material handling equipment. The unit cost of slate and shake shingles is relatively high. Thicker pieces of slate provide a better quality roof, but unit, handling and installation costs increase as the thickness of the slate increases. The unit cost of concrete tile is typically less than slate and shake shingles, but the concrete tiles are also typically heavier, resulting in higher handling and installation costs. Roofing tiles and specialty shingles also require special installation procedures specific to the tile and shingle configuration and type. Consequently, the installed cost of conventional roofing tiles, and slate and shake shingles, is relatively high due to high unit costs, and/or the high cost of labor to handle and install the tiles and shingles. As a result of these and other drawbacks and disadvantages known through the roofing industry, use of conventional roofing tiles and specialty shingles is typically limited to installation on relatively expensive buildings.
Prior roofing tiles and shingles made from plastic-composite materials have attempted to address some of the above-noted disadvantages of such conventional roofing materials. Composite roofing tiles are generally lightweight, and therefore, present the opportunity to reduce costs associated with handling and installation of relatively heavy conventional tiles and slate shingles. However, many prior composite roofing tile and shingle configurations are fabricated as “copies” of conventional tiles and shingles. Except for weight reduction in certain configurations, such prior composite tiles and shingles suffer from many of the same stacking, transportation, handling and installation difficulties as conventional tiles and shingles. The installed cost of such composite roofing materials is also relatively high. The unit cost of composite tiles and shingles is typically higher than the cost of tiles and shingles made from conventional materials, and when individual tiles and shingles are installed, the labor installation cost is the same as for installation of conventional roofing materials. In addition, prior composite roofing tiles and shingles often discolor in visibly evident patterns due to extended exposure to sun and weather. This discoloration results from the composition of the plastic-composite material, the molding process, and/or the configuration of the tiles. Visually detectable discoloration is often associated with uniform reinforcing or molding structures formed on the underside of the tiles or shingles, causing uniform patterns of regular transitions between thick and thin sections of the pieces that discolor non-uniformly upon extended exposure to outside elements. Due to the high cost of molds, fabrication of prior composite roofing tiles and shingles is typically limited to only a few configuration images. As a result, installation of such composite materials is often visibly evident due to the repeating image patterns as installed onto a roof, and the subsequent discoloration of the tiles and shingles. Prior composite roofing tiles and shingles also typically have difficulty meeting requirements for resistance to wind uplift as designated for roof construction in certain geographic areas of the country. As a result of the above-identified and other known disadvantages, prior composite roofing tiles and shingles have meet with only limited success in the market place, and the bulk of the roofing sold continues to be made from conventional materials.